public static function getChainByDefinition(Base $init_entity, $definition)
{
$chain = new QueryChain();
$chain->addElement(new QueryChainElement($init_entity));
$def_elements = explode('.', $definition);
$def_elements_size = count($def_elements);
$prev_entity = $init_entity;
$i = 0;
foreach ($def_elements as &$def_element) {
$is_last_elem = ++$i == $def_elements_size;
$not_found = false;
// all elements should be a Reference field or Entity
// normal (scalar) field can only be the last element
if ($prev_entity->hasField($def_element)) {
// field has been found at current entity
$field = $prev_entity->getField($def_element);
if ($field instanceof ReferenceField) {
$prev_entity = $field->getRefEntity();
} elseif ($field instanceof ExpressionField) {
// expr can be in the middle too
} elseif (!$is_last_elem) {
throw new SystemException(sprintf('Normal fields can be only the last in chain, `%s` %s is not the last.', $field->getName(), get_class($field)));
}
if ($is_last_elem && $field instanceof ExpressionField) {
// we should have own copy of build_from_chains to set join aliases there
$field = clone $field;
}
$chain->addElement(new QueryChainElement($field));
} elseif ($prev_entity->hasUField($def_element) && false) {
/** @deprecated */
// extend chain with utm/uts entity
$ufield = $prev_entity->getUField($def_element);
if ($ufield->isMultiple()) {
// add utm entity user.utm:source_object (1:N)
$utm_entity = Base::getInstance($prev_entity->getNamespace() . 'Utm' . $prev_entity->getName());
$chain->addElement(new QueryChainElement(array($utm_entity, $utm_entity->getField('SOURCE_OBJECT')), array('ufield' => $ufield)));
if ($ufield->getTypeId() == 'iblock_section' && substr($ufield->getName(), -3) == '_BY' && $prev_entity->hasUField(substr($ufield->getName(), 0, -3))) {
// connect next entity
$utm_fname = $ufield->getName();
$prev_entity = Base::getInstance('Bitrix\\Iblock\\Section');
} else {
$utm_fname = $ufield->getValueFieldName();
}
$chain->addElement(new QueryChainElement($utm_entity->getField($utm_fname), array('ufield' => $ufield)));
} else {
// uts table - single value
// add uts entity user.uts (1:1)
$uts_entity = Base::getInstance($prev_entity->getNamespace() . 'Uts' . $prev_entity->getName());
$chain->addElement(new QueryChainElement($prev_entity->getField('UTS_OBJECT')));
// add `value` field
$chain->addElement(new QueryChainElement($uts_entity->getField($def_element)));
}
} elseif (Base::isExists($def_element) && Base::getInstance($def_element)->getReferencesCountTo($prev_entity->getName()) == 1) {
// def_element is another entity with only 1 reference to current entity
// need to identify Reference field
$ref_entity = Base::getInstance($def_element);
$field = end($ref_entity->getReferencesTo($prev_entity->getName()));
$prev_entity = $ref_entity;
$chain->addElement(new QueryChainElement(array($ref_entity, $field)));
} elseif (($pos_wh = strpos($def_element, ':')) > 0) {
$ref_entity_name = substr($def_element, 0, $pos_wh);
if (strpos($ref_entity_name, '\\') === false) {
// if reference has no namespace, then it'is in the namespace of previous entity
$ref_entity_name = $prev_entity->getNamespace() . $ref_entity_name;
}
if (Base::isExists($ref_entity_name) && Base::getInstance($ref_entity_name)->hasField($ref_field_name = substr($def_element, $pos_wh + 1)) && Base::getInstance($ref_entity_name)->getField($ref_field_name) instanceof ReferenceField) {
/** @var ReferenceField $reference */
$reference = Base::getInstance($ref_entity_name)->getField($ref_field_name);
if ($reference->getRefEntity()->getFullName() == $prev_entity->getFullName()) {
// chain element is another entity with >1 references to current entity
// def like NewsArticle:AUTHOR, NewsArticle:LAST_COMMENTER
// NewsArticle - entity, AUTHOR and LAST_COMMENTER - Reference fields
$chain->addElement(new QueryChainElement(array(Base::getInstance($ref_entity_name), Base::getInstance($ref_entity_name)->getField($ref_field_name))));
$prev_entity = Base::getInstance($ref_entity_name);
} else {
$not_found = true;
}
} else {
$not_found = true;
}
} elseif ($def_element == '*' && $is_last_elem) {
continue;
} else {
// unknown chain
$not_found = true;
}
if ($not_found) {
throw new SystemException(sprintf('Unknown field definition `%s` (%s) for %s Entity.', $def_element, $definition, $prev_entity->getName()), 100);
}
}
return $chain;
}
